1. Field of the Invention
The present invention relates generally to cooling devices for devices that generate heat such as semiconductor chips, and particularly, to an apparatus that improves the capability and reliability of cooling devices for semiconductor chips. The invention is in the field of heat transfer and cooling of semiconductor chips used in computers and telecommunication equipment.
2. Description of the Prior Art
As the power of semiconductor chips increases, more efficient cooling device for semiconductor chips is therefore required. Current known cooling solutions have drawbacks in providing an adequate cooling to chips in small spaces and, drawbacks in lowering acoustic noise. For instance, U.S. Pat. Nos. 5,297,617, 5,309,983, and 5,445,215 each describe methods of using miniature “muffin fans” with multi-bladed propellers that drive cooling air toward heat collector fins at the periphery. These muffins fans tend to be nosier because the air is stirred up and pushed to the heat collector fins. U.S. Pat. No. 5,419,679 teaches a method using parallel disks to create air flow to draw air through an opening in an attached chassis for cooling electronic devices. U.S. Pat. No. 5,335,143 teaches a method using parallel disks between fins of a heat exchanger to provide cooling of chips. The arrangement is rather bulky, however, with only a small portion of a disk pumping air at any given time. U.S. Pat. No. 5,794,687 teaches a method of placing parallel disks in close fitting slots formed in a heat conducting housing. Methods of ducting incoming and outgoing air are additionally described.
U.S. Pat. No. 5,388,958 describes a “bladeless impeller” consisting of a plurality of disks and introduces a mechanism to transfer heat to the impeller shaft. However, the device needs to be positioned adjacent to an element to provide a complimentary surface to the disks to define a space in which pressure drop would occur on the operation of the impeller. U.S. Pat. No. 6,503,067 teaches a method using parallel disks to create laminar air flow for intake into an Internal combustion engine.
It would be highly desirable to provide a cooling apparatus for heat generating devices such as semiconductor chip devices that obviates the aforementioned deficiencies in the prior art.